1/* Target-dependent code for OpenBSD/mips64.
2
3   Copyright (C) 2004-2020 Free Software Foundation, Inc.
4
5   This file is part of GDB.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19
20#include "defs.h"
21#include "gdbtypes.h"
22#include "osabi.h"
23#include "regcache.h"
24#include "regset.h"
25#include "trad-frame.h"
26#include "tramp-frame.h"
27
28#include "obsd-tdep.h"
29#include "mips-tdep.h"
30#include "solib-svr4.h"
31
32/* The MIPS64 Floating-Point Quad-Precision format is similar to
33   big-endian IA-64 Quad-Precision format.  */
34#define floatformats_mips64_quad floatformats_ia64_quad
35
36#define MIPS64OBSD_NUM_REGS 73
37
38/* Core file support.  */
39
40/* Supply register REGNUM from the buffer specified by GREGS and LEN
41   in the general-purpose register set REGSET to register cache
42   REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
43
44static void
45mips64obsd_supply_gregset (const struct regset *regset,
46			   struct regcache *regcache, int regnum,
47			   const void *gregs, size_t len)
48{
49  const char *regs = (const char *) gregs;
50  int i;
51
52  for (i = 0; i < MIPS64OBSD_NUM_REGS; i++)
53    {
54      if (regnum == i || regnum == -1)
55	regcache->raw_supply (i, regs + i * 8);
56    }
57}
58
59/* OpenBSD/mips64 register set.  */
60
61static const struct regset mips64obsd_gregset =
62{
63  NULL,
64  mips64obsd_supply_gregset
65};
66
67/* Iterate over core file register note sections.  */
68
69static void
70mips64obsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
71					 iterate_over_regset_sections_cb *cb,
72					 void *cb_data,
73					 const struct regcache *regcache)
74{
75  cb (".reg", MIPS64OBSD_NUM_REGS * 8, MIPS64OBSD_NUM_REGS * 8,
76      &mips64obsd_gregset, NULL, cb_data);
77}
78
79
80/* Signal trampolines.  */
81
82static void
83mips64obsd_sigframe_init (const struct tramp_frame *self,
84			  struct frame_info *this_frame,
85			  struct trad_frame_cache *cache,
86			  CORE_ADDR func)
87{
88  struct gdbarch *gdbarch = get_frame_arch (this_frame);
89  CORE_ADDR sp, sigcontext_addr, addr;
90  int regnum;
91
92  /* We find the appropriate instance of `struct sigcontext' at a
93     fixed offset in the signal frame.  */
94  sp = get_frame_register_signed (this_frame,
95				  MIPS_SP_REGNUM + gdbarch_num_regs (gdbarch));
96  sigcontext_addr = sp + 32;
97
98  /* PC.  */
99  regnum = mips_regnum (gdbarch)->pc;
100  trad_frame_set_reg_addr (cache,
101			   regnum + gdbarch_num_regs (gdbarch),
102			    sigcontext_addr + 16);
103
104  /* GPRs.  */
105  for (regnum = MIPS_AT_REGNUM, addr = sigcontext_addr + 32;
106       regnum <= MIPS_RA_REGNUM; regnum++, addr += 8)
107    trad_frame_set_reg_addr (cache,
108			     regnum + gdbarch_num_regs (gdbarch),
109			     addr);
110
111  /* HI and LO.  */
112  regnum = mips_regnum (gdbarch)->lo;
113  trad_frame_set_reg_addr (cache,
114			   regnum + gdbarch_num_regs (gdbarch),
115			   sigcontext_addr + 280);
116  regnum = mips_regnum (gdbarch)->hi;
117  trad_frame_set_reg_addr (cache,
118			   regnum + gdbarch_num_regs (gdbarch),
119			   sigcontext_addr + 288);
120
121  /* TODO: Handle the floating-point registers.  */
122
123  trad_frame_set_id (cache, frame_id_build (sp, func));
124}
125
126static const struct tramp_frame mips64obsd_sigframe =
127{
128  SIGTRAMP_FRAME,
129  MIPS_INSN32_SIZE,
130  {
131    { 0x67a40020, ULONGEST_MAX },		/* daddiu  a0,sp,32 */
132    { 0x24020067, ULONGEST_MAX },		/* li      v0,103 */
133    { 0x0000000c, ULONGEST_MAX },		/* syscall */
134    { 0x0000000d, ULONGEST_MAX },		/* break */
135    { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
136  },
137  mips64obsd_sigframe_init
138};
139
140
141static void
142mips64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
143{
144  /* OpenBSD/mips64 only supports the n64 ABI, but the braindamaged
145     way GDB works, forces us to pretend we can handle them all.  */
146
147  set_gdbarch_iterate_over_regset_sections
148    (gdbarch, mips64obsd_iterate_over_regset_sections);
149
150  tramp_frame_prepend_unwinder (gdbarch, &mips64obsd_sigframe);
151
152  set_gdbarch_long_double_bit (gdbarch, 128);
153  set_gdbarch_long_double_format (gdbarch, floatformats_mips64_quad);
154
155  obsd_init_abi(info, gdbarch);
156
157  /* OpenBSD/mips64 has SVR4-style shared libraries.  */
158  set_solib_svr4_fetch_link_map_offsets
159    (gdbarch, svr4_lp64_fetch_link_map_offsets);
160}
161
162void _initialize_mips64obsd_tdep ();
163void
164_initialize_mips64obsd_tdep ()
165{
166  gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_OPENBSD,
167			  mips64obsd_init_abi);
168}
169